Bootstrap图标、下拉菜单、按钮组、按钮式下拉菜单

1.图标使用

<span class="glyphicon glyphicon-search" aria-hidden="true"></span>

.glyphicon 公共类 .glyphicon-search 相应的图标 aria-hidden="true" 意思是让图标只是显示，辅助设备不用读。

.sr-only 类让其在视觉上表现出隐藏的效果

部分

所有图标查询 https://v3.bootcss.com/components/

2.下拉菜单

向下弹出

<div class="dropdown">
  <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="true">
    Dropdown
    <span class="caret"></span>
  </button>
  <ul class="dropdown-menu" aria-labelledby="dropdownMenu1">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
    <li role="separator" class="divider"></li>
    <li><a href="#">Separated link</a></li>
  </ul>
</div>

向上弹出

<div class="dropup">
  <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu2" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropup
    <span class="caret"></span>
  </button>
  <ul class="dropdown-menu" aria-labelledby="dropdownMenu2">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
    <li role="separator" class="divider"></li>
    <li><a href="#">Separated link</a></li>
  </ul>
</div>

下拉菜单中的标题

<ul class="dropdown-menu" aria-labelledby="dropdownMenu3">
  ...
  <li class="dropdown-header">Dropdown header</li>
  ...
</ul>

分割线

<ul class="dropdown-menu" aria-labelledby="dropdownMenuDivider">
  ...
  <li role="separator" class="divider"></li>
  ...
</ul>

禁用菜单

<ul class="dropdown-menu" aria-labelledby="dropdownMenu4">
  <li><a href="#">Regular link</a></li>
  <li class="disabled"><a href="#">Disabled link</a></li>
  <li><a href="#">Another link</a></li>
</ul>

3. 按钮组

按钮颜色：btn-default btn-primary btn-success btn-info btn-warning btn-danger

<div class="btn-group" role="group" aria-label="...">
  <button type="button" class="btn btn-default">Left</button>
  <button type="button" class="btn btn-default">Middle</button>
  <button type="button" class="btn btn-default">Right</button>
</div>

按钮的大小

<div class="btn-group btn-group-lg" role="group" aria-label="...">...</div>
<div class="btn-group" role="group" aria-label="...">...</div>
<div class="btn-group btn-group-sm" role="group" aria-label="...">...</div>
<div class="btn-group btn-group-xs" role="group" aria-label="...">...</div>

嵌套下拉菜单

<div class="btn-group" role="group" aria-label="...">
  <button type="button" class="btn btn-default">1</button>
  <button type="button" class="btn btn-default">2</button>

  <div class="btn-group" role="group">
    <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
      Dropdown
      <span class="caret"></span>
    </button>
    <ul class="dropdown-menu">
      <li><a href="#">Dropdown link</a></li>
      <li><a href="#">Dropdown link</a></li>
    </ul>
  </div>
</div>

按钮组垂直排列

<div class="btn-group-vertical" role="group" aria-label="...">
  ...
</div>

4.按钮式下拉菜单

<!-- Single button -->
<div class="btn-group">
  <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Action <span class="caret"></span>
  </button>
  <ul class="dropdown-menu">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
    <li role="separator" class="divider"></li>
    <li><a href="#">Separated link</a></li>
  </ul>
</div>

5.分裂式按钮下拉菜单

<!-- Split button -->
<div class="btn-group">
  <button type="button" class="btn btn-danger">Action</button>
  <button type="button" class="btn btn-danger dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    <span class="caret"></span>
    <span class="sr-only">Toggle Dropdown</span>
  </button>
  <ul class="dropdown-menu">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
    <li role="separator" class="divider"></li>
    <li><a href="#">Separated link</a></li>
  </ul>
</div>

尺寸

<!-- Large button group -->
<div class="btn-group">
  <button class="btn btn-default btn-lg dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Large button <span class="caret"></span>
  </button>
  <ul class="dropdown-menu">
    ...
  </ul>
</div>

<!-- Small button group -->
<div class="btn-group">
  <button class="btn btn-default btn-sm dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Small button <span class="caret"></span>
  </button>
  <ul class="dropdown-menu">
    ...
  </ul>
</div>

<!-- Extra small button group -->
<div class="btn-group">
  <button class="btn btn-default btn-xs dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Extra small button <span class="caret"></span>
  </button>
  <ul class="dropdown-menu">
    ...
  </ul>
</div>